Guerbet meadowfoam esters

ABSTRACT

The present invention deals with the certain novel esters which are prepared by the reaction of a guerbet alcohol and meadowfoam fatty, methyl ester or triglyceride. These materials are useful as cosmetic ingredients where outstanding liquidity, resistance to oxidation, and minimal taste and odor variation are required. This combination of properties make these compounds excellent candidates as additives to personal care products like skin care oils and lipsticks.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention deals with the certain novel esters which areprepared by the reaction of a guerbet alcohol and meadowfoam fatty,methyl ester or triglyceride. These materials are useful as cosmeticingredients where outstanding liquidity, resistance to oxidation, andminimal taste and odor variation are required. This combination ofproperties make these compounds excellent candidates as additives topersonal care products like skin care oils and lipsticks.

2. Description of the Art Practices

Guerbet alcohols have been known for many years. Over the years therehave been a number of derivatives patented. U.S. Pat. No. 4,868,236 toO'Lenick discloses a guerbet citric ester and polymers thereof useful inplastic lubrication.

U.S. Pat. No. 4,425,458 to Lindner and O'Lenick teaches that specificguerbet esters can be used as polycarbonate lubricants.

The selection of an ester for use in pigmented products requires thatthere be a significant number of carbon atoms present to get the wettingand oily properties desired. Fatty esters of guerbet alcohols andsaturated fatty acids results in the preparation of esters which areliquid but not sufficiently hydrophobic (that is they do not have enoughcarbon atoms present) or if there are enough carbon atoms present, theproducts are slushy or solid at ambient temperatures.

Selecting unsaturated acids, like oleic acid, to make guerbet estersresults in the desired liquidity, but two additional problems areencountered, (a) there is not enough hydrophoblcity since the number ofcarbon atoms is limited to 18, and (b) the acid undergoes pronounceddegradation in a process referred to as "rancidity", making themunacceptable for applications where odor and taste is an issue. Therecent availability of meadowfoam oil, with it's 20 to 22 carbon atomsand the specific location of it's double bonds, and it's reaction withthe regiospecific beta branch of guerbet alcohols results in thepreparation high molecular weight liquid stable ester, acceptable foruse in pigmented personal care applications, like make-up and lipstick.

None of the prior compounds possess the critical meadowfoam carboxymoiety combined with the guerbet linkage in the molecule. Molecules ofthe current invention have guerbet substitution patterns in the alcoholand the meadowfoam alkyl group in the acid portion of the molecule.

THE INVENTION

This invention relates to a particular group of highly branched,unsaturated esters made by the reaction of a guerbet alcohol andmeadowfoam oil, meadowfoam methyl ester or meadowfoam fatty acid. Theterms meadowfoam oil, fatty acid or methyl ester as used herein refer toa specific alkyl distribution of the groups which is are native to aplant limnathes Alba, commonly called meadowfoam oil. Meadowfoam oil isharvested from a plant and sold commercially by The Fanning Corporationunder the tradename "Fancor Meadowfoam".

The unique structure of the oil coupled with the proper selection of theguerbet alcohol chosen to make the ester results in a liquid ester withoxidative stability heretofore unattainable. The fatty distribution ofthe oil ranges from 20 to 22 carbons and has unsaturation in specificlocations. The oil contains 97% by weight higher unsaturated alkylgroups. Typically, meadowfoam oil contains 60-65% of a twenty carbonmono-carboxy acid having one unsaturation between carbon 5 and 6.Additionally, it contains 12-20% of a twenty two carbon mono-carboxyacid having one unsaturation between either carbon 5 and 6, or carbon 13and 14 and 15-28% of a twenty two carbon mono-carboxy acid having oneunsaturation between both carbon 5 and 6, or carbon 13 and 14. Thecombination of the fact that there are 20 to 22 carbon atoms in thegroup leads to lack of volatility, the presence of unsaturation leads toliquidity and the fact that the di-unsaturated moieties are notconjugated leads to outstanding oxidative stability.

Additional aspects of the invention is the application of thesematerials as personal care applications were the specific properties ofan ester having a guerbet derived branching on the alcohol portion ofthe molecule and the unique distribution of the meadowfoam on the otherresult in superior liquidity, lubricity, and outstanding oxidativestability.

The compounds of the current invention are specific guerbetalcohol/meadowfoam esters conforming to the following structure;##STR1## wherein R is

60-65% by weight --(CH₂)₃ --CH═CH--(CH₂)₁₃ --CH₃

12-20% by weight a mixture of

    --(CH.sub.2).sub.3 --CH═CH--(CH.sub.2).sub.15 --CH.sub.3

and

    --(CH.sub.2).sub.11 --CH═CH--(CH.sub.2).sub.7 --CH.sub.3

and

15-28% by weight

    --(CH.sub.2).sub.3 --CH═CH--(CH.sub.2).sub.6 --CH═CH--(CH.sub.2).sub.6 --CH.sub.3 ;

a and b are independently integers ranging from 4 to 20.

PREFERRED EMBODIMENT

In a preferred embodiment a and b are each 8.

In another preferred embodiment a, b are each 6.

In another preferred embodiment a, b are each 4.

In still another preferred embodiment a, b are each 10.

In another preferred embodiment a, b are each 20.

The invention also teaches that an ester can be made by theesterification reaction of a guerbet alcohol conforming to the followingstructure; ##STR2## a and b are independently integers ranging from 4 to20; and meadowfoam oil.

In a preferred embodiment the esterification is conducted at atemperature of between 150 and 210 C.

In another preferred embodiment the esterification is conducted usingstannous oxylate as a catalyst.

EXAMPLES

RAW MATERIALS

Guerbet Alcohols

Guerbet Alcohols are regiospecifically beta branched alcohols. They havebeen known since the 1890's when Marcel Guerbet first synthesized them.(M. Guerbet, C. R. Acad. Sci. Paris, 128, 511; 1002 (1899)). Thesematerials are high in molecular weight and are liquid to very lowtemperatures. The guerbet reaction gives very specific branching in thealcohol as shown; ##STR3##

As can be seen by the above reaction the molecules have substitution onthe second carbon from the hydroxyl group. This branching has been foundto be critical to the preparation of a product having the desiredlubrication and oxidative stability properties. If the branching were onthe same carbon as the hydroxyl group, the hydroxyl group would be asecondary one and would be very hindered and has low reactivity. As onemoves the branch position away from the beta carbon, the liquidity,lubricity and metal substantivity decreases. If the branch is loweralkyl like methyl in some oxo alcohols, there is little increase in theliquidity, lubricity and metal substantivity over normal alcohols havingthe same number of carbons. Additionally, the oxo process gives onlysome beta branching (between 1 and 28%) the guerbet process givesessentially 100% product.

Guerbet alcohols that are the reaction product of one specific rawmaterial alcohol will result in a so called "homo-guerbet". In this caseR and R' are identical. If the starting alcohols used in the guerbetreaction are of differing molecular weights a so called "hetero-guerbet"results. This type o guerbet has a mixed distribution of all possiblecombinations of alcohols. For this reason R and R' in the genericformula may be the same or different. ##STR4## Guerbet alcohols areavailable commercially from Nova Molecular Technologies Janesville, Wis.They are marketed under the following commercial names:

    ______________________________________                                        Example    Commercial Name a      b                                           ______________________________________                                        1          Nova            3      3                                                      Guerbet C10                                                        2          Nova            4      4                                                      Guerbet C12                                                        3          Nova            5      5                                                      Guerbet C14                                                        4          Nova            6      6                                                      Guerbet C16                                                        5          Nova            7      7                                                      Guerbet C18                                                        6          Nova            8      8                                                      Guerbet C20                                                        7          Nova            14     14                                                     Guerbet C32                                                        ______________________________________                                    

Meadowfoam Oil

Meadowfoam Oil can be used as a triglyceride,which is the oil asprovided, reacted with methanol in processes known to those skilled inthe art to make methyl ester, or reacted using technology known in theart to make carboxylic acids. The CAS number of meadowfoam oil is153065-40-8.

The choice of triglyceride, acid or methyl ester does not change thestructure of the resultant ester. It does however change the by-productproduced. In the case of the triglyceride, glycerine is produced, in thecase of the acid water is produced and in the case of the methyl estermethanol is produced.

Ester Synthesis

The esterification reaction is carried out using an excess of alcohol ormeadowfoam or more typically using an equivalent of each. Theesterification reaction can be carried out with or without catalyst,however when no catalyst is used the reaction times are protracted.Catalysts like benzene sulfonic acid, tin, sulfuric acid, tin salts andthe like can be used. The most satisfactory catalyst is stannousoxylate.

General Procedure--Meadowfoam Oil

To the specified number of grams of guerbet alcohol (examples 1-7) isadded then 354.0 grams of the meadowfoam oil. Next add 0.1% stannousoxylate based upon the total weight of the batch after all ingredientshave been charged, under agitation. The temperature of the mass israised to 150°-200° C. and glycerine is stripped off under vacuum. Theacid value and hydroxyl value drop to vanishingly small values, and thesaponification value increases to theoretical.

The products are clear liquids and are liquid to extraordinarytemperatures. They exhibit outstanding lubrication properties and areoutstanding viscosity index modifiers.

    ______________________________________                                                      Guerbet Alcohol                                                 Example         Example  Grams                                                ______________________________________                                         8              1        157.0                                                 9              2        185.0                                                10              3        213.0                                                11              4        241.0                                                12              5        269.0                                                13              6        297.0                                                14              7        465.0                                                ______________________________________                                    

General Procedure--Meadowfoam Oil

To the specified number of grams of guerbet alcohol (examples 1-7) isadded then 354.0 grams of the meadowfoam fatty acid. Next add 0.1%stannous oxylate based upon the total weight of the batch after allingredients have been charged, under agitation. The temperature of themass is raised to 180°-200° C. and water is stripped off under vacuum.The acid value and hydroxyl value drop to vanishingly small values, andthe saponification value increases to theoretical.

The products are clear liquids and are liquid to extraordinarytemperatures. They exhibit outstanding lubrication properties and areoutstanding viscosity index modifiers.

    ______________________________________                                                      Guerbet Alcohol                                                 Example         Example  Grams                                                ______________________________________                                        15              1        157.0                                                16              2        185.0                                                17              3        213.0                                                18              4        241.0                                                19              5        269.0                                                20              6        297.0                                                21              7        465.0                                                ______________________________________                                    

Liquid products which contain unsaturation are subject to an oxidationprocess referred to as rancidity. The double bond (conjugated orunconjugated) present for the desired liquidity is oxidized to aldehydesand ketones which react to form compounds causing bad color, odor andtaste. In many applications including lipsticks, mal odor and mal tasteare major problems, but liquidity and hydrophobicity and liquidity aredesired. The presence of the aldehydic rancidity by-products produceunacceptable odor, color and taste components have a profound effectupon these properties at very minute concentrations. Studies have shownthat the part per billion levels of some aldehydic compounds causeunacceptable properties.

RANCIDITY TESTING

Rancidity was tested using gas chromotography on the head space abovethe product stored at specific conditions looking for degradationproducts. (Addition of 5 grams product to be tested to a 100 ml bottleequipped with a rubber septum top stored for 3 months)

    ______________________________________                                        Temperature 20 C.                                                                        Aldehyde                                                                      (Head Space                                                        Material   analysis)   Odor       Taste                                       ______________________________________                                        Example 12 None Detected                                                                             Good       Good                                        Example 20 None Detected                                                                             Good       Good                                        Example 11 None Detected                                                                             Good       Good                                        Unsaturated Compounds                                                         Oleic acid -                                                                              80 ppm     Fair       Fair                                        Guerbet 20 Ester                                                              Oleic Acid 100 ppm     Unacceptable                                                                             Fair                                        Guerbet 16 ester                                                              Tridecyl Oleate                                                                           90 ppm     Fair       Fair                                        TMP Trioleate                                                                            120 ppm     Unacceptable                                                                             Unacceptable                                ______________________________________                                        Temperature: 50 C.                                                                       Aldehyde                                                           Material   (Head Space)                                                                              Odor       Taste                                       ______________________________________                                        Example 12 None Detected                                                                             Good       Good                                        Example 20 None Detected                                                                             Good       Good                                        Example 11 None Detected                                                                             Good       Good                                        ______________________________________                                        Unsaturated Compounds                                                                    Aldehyde                                                                      (Head Space                                                        Material   analysis)   Odor       Taste                                       ______________________________________                                        oleic acid 200 ppm     Unacceptable                                                                             Unacceptable                                C-20 Guerbet                                                                  ester                                                                         Oleic Acid 175 ppm     Unacceptable                                                                             Fair                                        C-16 Guerbet                                                                  ester                                                                         Tridecyl Oleate                                                                          220 ppm     Unacceptable                                                                             Unacceptable                                TMP Trioleate                                                                            210 ppm     Unacceptable                                                                             Unacceptable                                ______________________________________                                         Oleic Acid/C20 Guerbet ester is the reaction product of (Raw material         example 6) and oleic acid.                                                    Oleic Acid/C16 Guerbet ester is the reaction product of (Raw material         example 4) and oleic acid.                                                    TMP trioleate is trimethylol propane tri oleate and is an item of             commerce.                                                                

I claim:
 1. An ester which conforms to the following structure: ##STR5##wherein: R is6- 65% by weight --(CH₂)₃ --CH═CH--(CH₂)₁₃ --CH₃ 12-20% byweight a mixture of

    --(CH.sub.2).sub.3 --CH═CH--(CH.sub.2).sub.15 --CH.sub.3

and

    --(CH.sub.2).sub.11 --CH═CH--(CH.sub.2).sub.7--CH.sub.3

and15-28% by weight

    --(CH.sub.2).sub.3 --CH═CH--(CH.sub.2).sub.6 --CH═CH--(CH.sub.2).sub.6 --CH.sub.3 ;

a, b, c and d are independently integers ranging from 4 to
 20. 2. Anester of claim 1 wherein a and b are each
 8. 3. An ester of claim 1wherein a, b are each
 6. 4. An ester of claim 1 wherein a, b are each 4.5. An ester of claim 1 wherein a, b are each
 10. 6. An ester of claim 1wherein a, b are each
 20. 7. An ester made by the esterificationreaction of a guerbet alcohol conforming to the following structure;##STR6## a and b are independently integers ranging from 4 to 20; andmeadowfoam oil.
 8. An ester of claim 7 wherein said esterification isconducted at a temperature of between 150° and 210° C.
 9. An ester ofclaim 7 wherein said esterification is conducted using stannous oxylateas a catalyst.
 10. An ester of claim 7 wherein a and b are each
 8. 11.An ester of claim 7 wherein a, b are each
 6. 12. A ester of claim 7wherein a, b are each
 4. 13. A ester of claim 7 wherein a, b are each10.
 14. A ester of claim 7 wherein a, b are each 20.